Ignition distributor with radially removable contact mechanism and terminal means



June 1970 HAN8-DIETER BASTAM ETAL 3,517,

IGNITION DISTRIBUTOR WITH HADIALLY REMOVABLE cou'mc'r MBQHAH'IEM ANDTERMINAL MEANS filed Nov. 13, 1%?

rbwwATmRA/EY United States Patent "ice B 90,037 Int. Cl. H01h 19/04,19/62 US. Cl. 20019 8 Claims ABSTRACT OF THE DISCLOSURE The electricfuel injection system of a multicylinder internal combustion enginereceives signals from a signal generating assembly which includes a tripmounted on the shaft of the ignition distributor and a carrier which isremovably inserted into the base of the ignition distributor andincludes a plate located in a plane which is normal to the shaft. Theplate supports two movable contacts which are biased against twostationary contacts. Signals are generated in response to each halfrevolution of the shaft when the trip causes one of the movable contactsto move away from the associated stationary contact. The plate iswithdrawable from the base by moving radially of and away from theshaft.

The present invention relates to multi-cylinder internal combustionengines in general, and more particularly to improvements in internalcombustion engines which are provided with electrically operated fuelinjection systems. Still more particularly, the invention relates toimprovements in internal combustion engines wherein the electroniccontrol unit of the fuel injection system receives signals or impulsesfrom the ignition distributor.

It is already known to provide a. multi-cylinder internal combustionengine with a fuel injection system wherein the operation ofelectromagnetic fuel injection nozzles is regulated by a control unitwhich receives signals from the ignition distributor. The control unitcomproses a monostable tilting stage which includes a set oftransistors.

The tilting stage assumes its unstable condition at least once duringeach revolution of the engine camshaft to thereby determine the lengthof intervals during which the fuel injection nozzles remain open. Thetilting stage automatically reassumes its stable condition to therebyclose the fuel injection nozzles after elapse of an interval whoseduration is determined by electric energy storing devices. Certainengines which embody the just outlined fuel injection system are furtherprovided with a signal generator which sends signals to the control unitand is permanently incorporated in the ignition distributor. In abattery-operated ignition distributor, the distributor shaft whichreceives motion from the engine camshaft carries a trip which operates aswitch forming part of the signal generator. Problems arise when theignition distributor is provided with a spark advance mechanism whichmust change the position of the distributor cam with reference to thedistributor shaft or the position of the breaker plate with reference tothe base of the ignition'distributor. The spark advance mechanismrenders it difficult to gain access to the switch of the signalgenerator for the control unit of the fuel injection system. Inparticular the spark advance mechanism renders it difficult to inspectthe signal generator at regular intervals. As a rule, the spark advancemechanism must be dismantled and removed from the base of the ignitiondistributor in order to afford access to the signal generator.

3,517,142 Patented June 23, 1970 Summary of the invention It is anobject of the present invention to provide an ignition distributor formulti-cylinder internal combustion engines which employ electrical fuelinjection systems and to provide the ignition distributor with a signalgenerating assembly for the control unit of the fuel injection systemwhereby the ignition distributor and the signal generating assembly areconstructed and assembled in such a way that the latter can be readilydetached from the ignition distributor without necessitating evenpartial dismantling of the remaining parts of the ignition distributor.

Another object of the invention is to provide an ignition distributorwhich is provided with a spark advance mechanism and wherein the signalgenerating assembly for the fuel injection system is installed in such away that its parts can be removed from the base of the ignitiondistributor without necessitating even partial dismantling of the sparkadvance mechanism.

A further object of the invention is to provide a removable signalgenerating assembly which can be used to transmit signals to the controlunits of presently known electrical fuel injection systems formulti-cylinder internal combustion engines.

The invention is embodied in an ignition distributor for multi-cylinderinternal combustion engines of the type having an electricallycontrolled fuel injection system which preferably includes knownelectromagnetically operated fuel injection nozzles arranged to open inresponse to impulses transmitted by the transistorized output stage ofan electronic control unit. The ignition distributor comprises acustomary base which is provided with an opening, a distributor shaftrotatably mounted in a bushing provided in the base and arranged tooperated a customary rotor through the intermediary of a distributor camand a spark advance mechanism, and a novel signal generating assemblyfor the injection system of the engine. The signal generating assemblyincludes actuating means which preferably resembles a trip or cammounted on the distributor shaft in the base of the ignitiondistributor, a preferably plate-like carrier which is removably insertedinto the opening of the base, and switch means including stationarycontact means mounted on the carrier and movable contact means providedon the carrier and operable by the trip to eifect opening and closing ofthe switch means in predetermined angular positions of the distributorshaft. The switch means preferably includes two switches alternatelyopen in response to each half revolution of the distributor shaft.

The carrier is inserted into the base in a manner similar to that inwhich a drawer is inserted into a table and is withdrawable radiallyoutwardly of and away from the distributor shaft. In order to properlylocate the movable contacts with reference to the tip on the distributorshaft, the carrier is provided with a cutout or recess which receivesthe bushing for the distributor shaft when the carrier is fully insertedinto the base of the ignition distributor. Terminals which are connectedto the stationary and movable contacts of the switch means extend into asocket provided on the carrier, and the socket can be coupled with aplug which contains conductors arranged to transmit signals to thecontrol unit of the fuel injection system.

The novel features which are considered as characteristic of theinvention are set forth in particular in the appended claims. Theimproved ignition distributor itself, however, both as to itsconstruction and its mode of operation, together with additionalfeatures and advantages thereof, will be best understood upon perusal ofthe following detailed description of a specific embodiment withreference to the accompanying drawing.

Brief description of the drawing Description of the preferred embodimentThe ignition distributor of FIG. 1 comprises a cast aluminum base orhousing 1 provided with a tubular extension or neck 2 which can beinserted into the block of a multi cylinder internal combustion engine.The neck 2 accommodates a distributor shaft which is rotatable in abushing 4 and carries at its outer end a coupling 3 which can be drivenby a gear on the engine camshaft. The shaft 5 extends into the base 1and supports a weight carrying plate 6a .for advance Weights 6 whichform part of a spark advance mechanism serving to control a distributorcam 7. The cam 7 cooperates with a distributor lever 8 supported by abreaker plate 9 which is installed in the base 1. The breaker plate 9also carries a fixed contact 10 which cooperates with the distributorlever 8.

The open end of the base 1 is connected with a plastic cap 11 which issecured thereto by two cap clamp springs 12 (only one shown). The cap 11carries a center high tension terminal 13 which is connected with thesecondary winding of an ignition coil (not shown) and four outer hightesion termials 14 connected to the engine spark plugs. A rotor 15 ofplastic material rotates with the distributor cam 7 and carries anembedded shielding resistor 16 which directs the high voltage surgesfrom the ignition coil to the individual outer terminals 14.

The heretofore described parts of the ignition distributor are wellknown in the art. In addition, the ignition distributor serves as ameans for transmitting signals to the fuel injection nozzles of theelectrical fuel injection system for the internal combustion engine. Thesignal generator assembly of the ignition distributor comprises atubular actuating cam or trip 20 which is mounted on the distributorshaft 5 and cooperates with two pivotable or movable contacts 21, 22.The contacts 21, 22 are afiixed to blocks 23 of insulating material andare electrically connected to leaf springs by means of rivets 24 passingthrough the respective blocks 23. This is best shown in FIG. 2. The leafsprings 25 urge the projections or lobes 26 of insulating blocks 23against the periphery of the trip 20 and to thereby hold the movablecontacts 21, 22 in engagement with stationary contacts 27. When thedistributor shaft 5 rotates, the contacts 21, 22 are moved alternatelyaway from the respective fixed contacts 27 in response to each rotationof the shaft 5 through 180 degrees because the trip 20' pivots theblocks 23. Thus, the signal generator assembly comprises two switchesincluding the movable contacts 21, 22 and the corresponding stationarycontacts 27, and each of these switches produces a signal in response tomovement of the contact 21 or 22 away from the corresponding stationarycontact 27.

In order to permit rapid and convenient inspection of movable contacts21, 22 and stationary contacts 27 after extended periods of use, thecontacts 21, 22, their blocks 23, leaf springs 25 and stationarycontacts 27 are supported by a plate-like carrier 30 to form therewith aselfsupporting unit which is best shown in FIG. 3. This unit can beinserted through an opening 1a in the base 1 in a direction radiallytoward the distributor shaft 5 and can be Withdrawn, not unlike adrawer, in a direction radially of and away from the shaft 5. Thecarrier 30 is located in a plane which is normal to the axis of theshaft 5 and is provided with two bent-over lugs 3-1 which are coupled toan arcuate bracket 32 whose configuration conforms to the outline of thebase 1. This bracket 32 is provided with a plastic Coupling member inthe form of a socket 33 which surrounds portions of three substantiallyL-shaped terminals 34. Each terminal 34 comprises a horizontal leg (asviewed in FIG. 1) which extends toward the distributor shaft 5 when thecarrier 30 is inserted into the base 1. The central terminal 34 isconnected by means of a short cable 36 with a plate-like, conductor 35which connects the stationary contacts 27. Each of the two outerterminals 34 is connected with one of the movable contacts 21, 22through the intermediary of the respective leaf spring 25.

In order to insure that the movable contacts 21, 22 are properlypositioned with reference to the actuating trip 20, the carrier 30 isprovided with a centrally located centering cutout or recess 40 whichaccommodates the bushing 4 when the carrier is properly inserted intothe base 1. When in fully inserted position, the carrier 30 can bedetachably secured to the base 1 by means of two screws 41 or similarfasteners which extend through the bracket 32 and into tapped boresmachined into the base. The socket 33 can receive a male coupling memberor plug (not shown) which contains conductors connecting the terminals34 with the input of the electronic control unit in the fuel injectionsystem. Thus, the control unit will receive a signal in response toopening of the switch which includes the movable contact 21 or inresponse to opening of the switch which includes the movable contact 22.

A fuel injection system which can receive signals from the assembly asshown in the drawing is disclosed in the British patent specificationNo. 976,340.

Without further analysis, the foregoing will so fully reveal the gist ofthe present invention that others can, by applying current knowledge,readily adapt it for various applications without omitting featureswhich fairly constitute essential characteristics of the generic andspecific aspects of our contribution to the art and, therefore, suchadaptations should and are intended to be comprehended within themeaning and range of equivalence of the claims.

What is claimed as new and desired to be protected by Letters Patent isset forth in the appended claims:

1. An ignition distributor for multiple-cylinder internal combustionengines of the type having an electrically controlled fuel injectionsystem, comprising a substantially closed housing; a distributor shaftrotatably mounted in said housing and distributor means including adistributor actuating member mounted on said shaft and a distributormember cooperating with said distributor actuating member mounted onsaid shaft; a signal-generating assembly for the fuel injection systemincluding actuating means fixed to said shaftaxially displaced from saiddistributor means; switch means including stationary contact means andmovable contact means operable by said actuating means to effect openingand closing of said switch means in a predetermined angular position ofsaid shaft; a single carrier located in a plane substantially normal tosaid shaft and carrying said contact means and forming a unit therewith,said unit being removable in radial direction through an Opening in saidhousing without disassemblying said distributor means; a bracket fixedto said single carrier and closing said opening in said housing Whensaid unit is located within said housing; and means for removablysecuring said unit together with said bracket to said housing.

2. A combination as defined in claim 1, wherein said carrier is providedwith means for locating said movable contact means with reference tosaid actuating means.

3. A combination as defined in claim 2, wherein said locating meansincludes a recess provided in said carrier and further comprising abushing for said shaft provided in said base, said bushing extendinginto said recess.

4. A combination as defined in claim 1, wherein said actuating meanscomprises a trip afiixed to said shaft and each of said contact meanscomprises a pair of contacts, said movable contacts being arranged tomove alternately away from the corresponding stationary contacts inresponse to each half revolution of said shaft.

5. A combination as defined in claim 4, wherein said signal generatingassembly further comprises means for biasing said movable contactsagainst said trip.

6. A combination as defined in claim 5, wherein said signal generatingassembly further comprises a first terminal electrically connected toboth said stationary contacts and two additional terminals eachelectrically connected to one of said movable contacts.

7. An ignition distributor for multiple-cylinder internal combustionengines of the type having an electrically controlled fuel injectionsystem, comprising a substantially closed housing; a distributor shaftrotatably mounted in said housing and distributor means including adistributor actuating member mounted on said shaft and a distributormember cooperating with said distributor actuating member mounted onsaid shaft; a signal-generating assembly for the fuel injection systemincluding actuating means fixed to said shaft axially displaced fromsaid distributor means; switch means including stationary contact meansand movable contact means operable by said actuating means to effectopening and closing of said switch means in a predetermined angularposition of said shaft; a single carrier located in a planesubstantially normal to said shaft and carrying said contact means andforming a unit therewith, said unit being removable in radial directionthrough an opening in said housing without disassembling saiddistributor means; terminal means mounted on said single carrier outsideof said housing 6 and connected to said contact means so that saidterminal means are accessible from outside of said housing while saidunit is located within said housing.

8. A combination as defined in claim 7, wherein said coupling member isa socket which can be connected with 5 the plug of the electricalcontrol unit in said fuel injection system.

References Cited 10 UNITED STATES PATENTS 1,869,814 8/1932 Karkau 200-312,884,916 5/ 1959 Winkler. 2,936,744 5/1960 Paul et a1. 2,598,754 6/1952Booth. 2,795,658 6/1957 Ward.

2,833,872 5/ 1958 Oberholzer. 2,956,131 10/1960 Tabet. 2,981,244 4/ 1961Hendrickson.

FOREIGN PATENTS 1,294,906 4/ 1962 France.

279,341 2/ 1966 Australia.

ROBERT K. SHAEFER, Primary Examiner R. A. VANDEHYE, Assistant Examiner.

US. Cl. X.R 200166;12332

